Java Observable .deleteObserver (Observer o)

public void deleteObserver(Observer o)

//from  w w w  . ja  v a2s  .  c  o m

import java.util.Observable;
import java.util.Observer;

class ObservedObject extends Observable {
   private String watchedValue;
   
   public ObservedObject(String value) {
      watchedValue = value;
   }
   
   public void setValue(String value) {
      if(!watchedValue.equals(value)) {
         System.out.println("Value changed to new value: "+value);
         watchedValue = value;
         
         setChanged();
         notifyObservers(value);
      }
   }
}
class MainObserver implements Observer {
   public void update(Observable obj, Object arg) {
      System.out.println("Update called with Arguments: "+arg);
   }
}

public class Main{
   public static void main(String[] args) {
      ObservedObject watched = new ObservedObject("Original Value");
      MainObserver watcher = new MainObserver();

      watched.setValue("Value before addObserver");

      watched.addObserver(watcher);
      watched.setValue("Value after addObserver");
      watched.deleteObserver(watcher);
      watched.setValue("Value after deleteObserver");
   }
}